Preamplifier circuits can be implemented for a variety of purposes, such as to generate an overshoot current for writing data to a magnetic medium (e.g., a disk drive, such as a hard-disk drive). As an example, a preamplifier circuit can be configured to provide an output current pulse in response to an input current pulse, with the output current pulse having a magnitude that is amplified relative to the input current pulse by a gain factor. It can be desirable to tune such gain factor, such as based on requirements dictated by the preamplifier application. In addition, given the sensitivity of a given magnetic medium in a disk-write preamplifier application, it can likewise be desirable to tune a slew-rate associated with the output current pulse to avoid affecting data in adjacent tracks on the magnetic medium while still maintaining a rapid write speed. Such slew-rate can be tuned in typical preamplifier circuits based on the selecting different values for the gain resistor or input current pulse, which can thus also affect the gain of the output current pulse, or based on switching in additional current-pulse components to the input current pulse, which can provide timing conflicts.